HR: 1340h
AN: PP43A-0609    [Abstracts]
TI: A High-Resolution Climate Record for the Last Millennium From a Scottish Stalagmite
AU: * Fuller, L
EM: lxf340@bham.ac.uk
AF: School of Geography, Earth and Environmental Science, University of Birmingham, Edgbaston, Birmingham, B15 2TT United Kingdom
AU: Baker, A
EM: a.baker.2@bham.ac.uk
AF: School of Geography, Earth and Environmental Science, University of Birmingham, Edgbaston, Birmingham, B15 2TT United Kingdom
AU: Fairchild, I J
EM: i.j.fairchild@bham.ac.uk
AF: School of Geography, Earth and Environmental Science, University of Birmingham, Edgbaston, Birmingham, B15 2TT United Kingdom
AU: Mattey, D
EM: mattey@gl.rhul.ac.uk
AF: Department of Geology, Royal Holloway, University of London, Egham, Surrey, TW20 0EX United Kingdom
AU: Rowe, P J
EM: p.j.rowe@uea.ac.uk
AF: School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ United Kingdom
AU: Spoetl, C
EM: christoph.spoetl@uibk.ac.at
AF: University of Innsbruck, University of Innsbruck, Department of Geology, Innrain 52,, Innsbruck, 6020 Austria
AB: Stalagmites are recognised as important continental archives of palaeoenvironmental information, they can be accurately dated and their subterranean location means that they can accumulate undisturbed for thousands of years. This work takes advantage of the recent developments in the High-Resolution analysis technique of Laser Ablation Gas Chromatography Isotope Ratio Mass Spectrometry (LA-GC-IRMS) to produce High-Resolution stable isotope records and hence a climate record for Northwest Scotland. NW Scotland is a site located on the North Atlantic Seaboard and an area which is thought to be climatically sensitive, particularly in the relationships between precipitation and the NAO and temperature and ocean circulation via the North Atlantic Drift. Initial laser ablation d18O results on a 1000 year old annually laminated stalagmite show oxygen isotope variations in the stalagmite calcite which is greater than can be attributed to temperature change alone. This suggests that the stalagmite is recording a combination of environmental factors and highlights the need for detailed calibration of the modern cave system. An understanding of how these surface climate signals are transmitted through an 18O proxy to a stalagmite via the soil and groundwater system is essential. The cave system from which the stalagmite was sampled was monitored over a 12 month period. Surface and cave drip waters were collected and analysed for a variety of isotopic and geochemical parameters including d18O, dD, d13C. Cave climatology was monitored for temperature, humidity and carbon dioxide concentration. Drip rates were monitored in order to understand the hydrology of the overlying karst system. Initial monitoring results indicate a seasonally variable cave temperature (4-9 degrees C), high relative humidity (100 %); cave air CO2 concentration also follows a seasonal pattern. Waters collected from the surface show seasonal variation in d18O and d2H composition with more positive values in summer. Drip waters show little isotopic variation indicating a substantial degree of mixing in the epikarst. Monitoring suggests that the cave is sensitive to a number of parameters whose dominance may change through time. The role of ventilation and hence kinetic effects upon isotopic fractionation may also play a part.
UR: http://www.gees.bham.ac.uk/research/ascribe/
DE: 1040 Isotopic composition/chemistry
DE: 1094 Instruments and techniques
DE: 1620 Climate dynamics (3309)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting